// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/gl/gl_fence_nv.h"

#include "ui/gl/gl_bindings.h"

namespace gfx {

GLFenceNV::GLFenceNV()
{
    // What if either of these GL calls fails? TestFenceNV will return true.
    // See spec:
    // http://www.opengl.org/registry/specs/NV/fence.txt
    //
    // What should happen if TestFenceNV is called for a name before SetFenceNV
    // is called?
    //     We generate an INVALID_OPERATION error, and return TRUE.
    //     This follows the semantics for texture object names before
    //     they are bound, in that they acquire their state upon binding.
    //     We will arbitrarily return TRUE for consistency.
    glGenFencesNV(1, &fence_);
    ResetState();
}

bool GLFenceNV::ResetSupported()
{
    return true;
}

void GLFenceNV::ResetState()
{
    glSetFenceNV(fence_, GL_ALL_COMPLETED_NV);
    DCHECK(glIsFenceNV(fence_));
    glFlush();
}

bool GLFenceNV::HasCompleted()
{
    DCHECK(glIsFenceNV(fence_));
    return !!glTestFenceNV(fence_);
}

void GLFenceNV::ClientWait()
{
    DCHECK(glIsFenceNV(fence_));
    glFinishFenceNV(fence_);
}

void GLFenceNV::ServerWait()
{
    DCHECK(glIsFenceNV(fence_));
    ClientWait();
}

GLFenceNV::~GLFenceNV()
{
    DCHECK(glIsFenceNV(fence_));
    glDeleteFencesNV(1, &fence_);
}

} // namespace gfx
